Hi Salmo - Well what a coincidence! Just last week taken delivery of 1 mustache and 1 pendant type Oxymizer. Bad news is I had to buy them from USA and from two separate sellers and in total the whole experience came to over £100! Neither is pleasant to look at, but I think they do make some difference. The mustache is the easiest to wear although it is highly visible - being female I expected to prefer the pendant type, but the tubing on the pendant type is so thick & hard I have a problem getting it to stay in position over my ear and it's uncomfortable on my face. If you went ahead I would say buy a couple of the mustache type - the reason why I say buy a couple is that postage etc increased the costs big time and would probably be the same whether you buy one or a few.
I have no way of telling as of yet just how much difference they make as I have only tried them out around my lounge, plus tried sleeping with the mustache using 1LPM instead of my usual 2. It's walking/exercise where I really need it as I still desaturate to around 82-84% on 6LPM constant (Helios) if I walk at a decent pace or up the slightest incline. I also have a COPD blog and aim to blog re these and also the 'head set' type cannulas, soft hose cannulas etc when I get around to it.
The big Q now is where did I buy them from - I will have to get back to you later on that (haven't had breakfast yet). I tried a few sellers but once I input my UK address I invariably got a 'we do not ship outside of the USA' message. I remember one was from an E Bay seller - but I will look it back over my tracks later in the day and give you the links. In the meantime if you have any Q's let me know. Will be back with details later today.